Replication factor plays an important role in Hadoop file System. Replicating a block on multiple datanodes prevents loss of block when a particular datanode goes down.
This post describes how to check the replication factor that is actually set for a particular file in HDFS.

There are 2 ways:

    Using the HDFS Command Line.
    Using the HDFS Web Interface.

Using HDFS Command Line

The Second Column displays the Replication Factor.

Using HDFS Web Interface

Using the Browsefile link, just navigate to the path where the file is present.